mannesmann



(ModeL) 2 Sheets- 8heet 1.

R. MANNESMANIIL MANUFACTURE OF SEAMLESS IUBES.

No. 361,957. Patented Apr. 26, 1887.

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. Mus- (Model.) 2 Sheets-Sheet 2.

R. M ANNESMAN N. MANUPAGTURE 0F SEAMLESS TUBES. No. 361,957. 7 Patented Apr. 26, 1887.

UNITED STATES;

PATENT. OFFICE.

REINIIARD MANNESMANNZ-OF REMSOHEID, GERMANY.

MANUFACTURE OF SEAM Lass TUBES.-

SPBCIPICATION forming part of Letters Patent No. 361,957. dated April 26, 1887.

Application filed March 28, 1887. Serial No. 232,792. (115901,) "Patmted'in England January 1885, No. l,l6'l; in France Janunryfll, 1885. No. 168,433; ln Bolzlmu Jannnrylfl, 1895, No. 61,067; in Germany Jannary'fl'l, i885. No. 34,617; in Italy Jannary 26. I886, No. 7,925; in Luxembnrg June 20, 1885, No. 704; in Syaln August 21, 1886, No. 9,537, and in Austria-Hungary September 18, 1886 that a solid metallic blank suitably heated is passed endwise between diagonally acting" rolls the working-faces of which converge. I

havein another application described the combination for same purposes of such rolls with,

a comparatively slender rod adapted to be loosely contained within the tube in process of formation, the end of which rod abuts against and serves to hold back the solidcentral portion of the blank. I have also described in another application the employment of rolls of 2 5 the character referred to in combinationwith a conical, mandrel placed midway between the working-faces of the rolls and used for smoothing the inner surfaceand also'for determining the inner diameter of the tube. In those cases,

however, the holding-back bar or formingmandrel has always been a passive factor in the combinations described. The said factor has been prevented from endwise movement,

- and in some cases from rotatory movement,

though it has usually been left free to be rotated by the frictional bearing upon it of the rotating blank, within the tubular part -of whichit has been contained. a

Q I The present invention consists in the com 7 4o bination of diagonally-actingrolls having con-j vergent working-faces with a centrally-placed mandrel, which is preferably conical, and the surface of which is provided with spiral corrugations, preferably of increasing pitch; the

4.5 mandrel either being held stationary-or re-.

volved in the same direction as the blank, but at a slower speed, or revolved in the opposite direction from that of the blank for the purpose of causing the spiral corrugations in the not needldescrlpti'ou in detail herein. ,The accompanying drawings therefore embrace only't-hose features of construction which are .the convergent working-faces of two oppoconical mandrel engage the metal near the place within the blankwhere the tubnlar'formation is initiated, and to draw such metal forward, and thus co -operate with the external diagonally-acting'rolls informing a tube of prescribed interior and exterior diameter.

Machines for diagonally rolling metallic bars or blanks passed endwise between their working-faces have heretofore been used for various purposes, and, being well known, do

peculiar to diagonal rollingapparatnsembodying the presentinventlon.

The drawings are as follows: Figure 1 is a top view, and Fig. 2 is a side elevation, of a portion of a diagonal rolllng machine employing a mandrel the conical head ofjwhich is spirally grooved and is'placed midway between o sitely-inclined conical-r01 ls, the vertical planes 7 of the axes of which are parallel. Figs. 3,

4, 5, 6, and 7' are each top views, showing in horizontal section a metallic blank at various stages of iis'progress between the working faces of the rolls, during-which it is trans-- formed into a hollow body or tube-open from end to end. For convenience of description,it,is assumed that in the structure illustrated in the-drawings two diagonally-acting conical rolls are arranged upon either side of ahori'zontahmandrel, and that the vertical planesof the oppositely-inclined axes of the-rolls are parallel.

' It will of course be understood that the diagonally-acting rolls may be arranged one above and the other below the mandrel, and also that the vertical planes of the'axes of the rollsneednot necessarily be parallel. l

The working-faces of the conical rolls A a are generally provided with spiral corrugations, as shown in Fig. '3. 1

The blank B is roperlycentralized for de-, livery to the rolls y being placed within the guide-tube B, which is rigidly clamped to the tableBimmediatelyadjoining therolls. From' the guide-tube B the blank B is' fed into the wider end of the space between the working-l it v 361,957

faces of the rolls, and by the pinching effect to which it is immediately subjected has the concave recess b formed in its forward end. Soon after the formatiouof the concaverecess b the forward end of the blank is brought into collision with the conical mandrel O, which for a portion of its length is provided with a spiral groove or grooves, O, the pitch of which preferably becomes gradually coarser from the pointtoward the base of the cone.

The base of the mandrel is provided with the projecting tongue G, which is in the form of the frustum of a pyramid, and is loosely contained in the flaring rectangular socket d,

formed in the end of the mandrel-shaft D.

' At its opposite end the mandrel-shaft D is squared and loosely contained in the quadrangular socket 6, formed in the end of the shaft of the pinion E, and suitable gearing is provided for rotating the pinion E in such direc- 'mandrel acts in this particular, which can be done by-imparting rotation to the mandrel in the same direction as that of the blank, but at less speed. I On theother hand, it may be desirable in some cases to increase the effectivemess with which the spiral grooves perform their function, and to effect this result the mandrel can be rotated in the direction opposite to that of the direction of rotation of the blank. Y

Progressive stages in the transformation of the solid blank into a tube are illustrated in Figs. 3, 4, 5, 6, and 7. The mandrel may, if desired, be made ellipsoidal in cross-section, but is preferably made circular in cross-section, as represented in the drawings. It may be spirally grooved for its entire length or upon any portion of its surface, and its spiral grooving may have any desired pitch or variation in pitch. 7

The employment of a spirally-grooved mandrel as an active factor, in combination with the diagonally-acting rolls, for efi'ecting the transformation of a solid metallic blank into. a tube is especially desirable in operating upon -blanks composed of soft and ductile metals, and in operating upon such metals it will not in all cases be necessary to have any portion of the working-faces of the diagonallyacting rolls corrugated,'- although such corrugations may of course be provided, if desired.

It will be obvious that the spirally-grooved conical mandrel, held stationary or rotated at a different speed or in a different direction from that imparted to the blank by the diagonally-acting rolls, may be employed for the purpose of enlarging t e internal diameter of a hollow blank, and of co-operating with the diagonally-acting rolls in drawing out a hollow blank into a tube having a shell of prescribed thickness.

I claim as my invention- 1. In diagonal tube-rolling apparatus, the combination, as herein set forth, of diagonallyacting rolls the working-faces of which are suitably convergent with a grooved or corrugated mandrel interposed between opposite portions of the working-faces of said rolls, and

.means for holding the said mandrel stationary, or for rotating it at a different speed or in the opposite direction from the speed and direction of rotation acquired by a solid or hollow blank, duringits passage between the working-faces of the rolls.

2. The improvement in the art of transforming a solid metallic blank into a tube, which consists in progressively rolling and drawing the metal composing the exterior portion of the blank inwardly and forwardly over the pointed end of a grooved or corrugated mandrel by means of diagonallyacting rolls having suitably-convergent faces, and simultaneously drawing forward the metal from the interior portion of the blank by holding the said grooved or corrugated mandrel stationary, or by rotating it at a difierent speed or in the opposite direction from the speed and direction of rotation acquired by the blank in its passage between the converging working-faces of the rolls.

REINHARD MANNESMANN. Witnesses:

FRITZ KOEGEL, GUsTA'vE ALBERT OELRIcHs. 

